Piano action



' July 12,1927.

I M35311 C. E. CAMERON. JR

PIANO Aqm'lon Filed April 26, 1 923 IN VE N TOR (Ell/(u 1.6.9 Ewen Camwromfn Wm d ATTORNEY Patented Ju 12, 1927.

uNiTEosTA Es PATENT OFFICE.L

CHARLES EWEN CAMERON, JR., EAST ORANGE, NEW JERSEY.

PIANO ACTION.

Application-filed April 26, 1923. Serial no. 634,699.

Theinvention relates in general to an improved form of piano action and specifically relates to certain details ofconstruction in the mechanism for striking one of the piano strings by the actuation of its associated .key.

In tlie'following specificationand in the claims the term"keyc will be used to des ignate either i the manually actuated key,

commonly found in hand played instruhaimner and its associated mechanism located between the abstract and the string, andqto a novel arrangement of soft pedal construction for modifying the sound from one or more strings of the instrument.

Piano actions of the type herein disclosed include rather complicated meeha nism between the abstract and the string striking hammer. These known actions include certain wippens, jacks, links, and springs, together with numerous pivotal connections, each one of whieh contributes an increment of frictional resistance and which collectively require the expenditure of a material amount of actuating force to effect a playing operation of the device. Further in known forms of actions a part of the manual or mechanical force expended on any one of the keys is required to positively do work in dampening out the vibration of the hammer in its recoil from the string. All these factors act to render the old form of action extremely inefficient and eiiiciency is necessary especially in mechanically I played i nstruments.

Aside from this lack of economy in utilization of force expended, the multiplicity of separate parts increased the number of possible parts which may become worn or damaged and as a result such constructions are quite liable to become damaged, and can be repaired only by the skilled workmen and are not susceptible of being repaired at home by the unskilled. usual user. I

The primary ob'ect offthe invention is to simplify the present form of piano action while retaining all of the advantages of the present type.

. Incidental to this general desideratum the invention has for'other objects the reducing of the number of parts between the abstract and the hammer to a single element so as to nnnimize'points of possible frictional resistance and in general to provide a-form of action in which theactuat-ing force employed on a key is economically utilized almost entirely to effect a movement of the hammer in its string striking movement. Further featuring simplicity in construction another object of the invention is to provide a piano I action in which the usual multiplicity of adjustments have been reduced to a single,

easily manipulated regulation and in the present disclosure this regulation is confined to the readily accessible abstract of the action.

Another object of the invention is to provide in connection with the hammer a construction which will minimize any tendency towards blocking and in which the tendency of the hammer to vibrate on its recoil is dampened out by frictional resistance which does not interfere with the succeeding actuation of the hammer and which contributes tothe object of efliciency in operation by not utilizing any of the energy of the hammer actuating mechanism for the purpose of maintaining the hammer in its normal inoperative position.

Still-another object of the invention is to provide a piano action in which the parts can be readily demountcd for repair and substitution and in which certain wearable orreadily damaged parts can be organized as parts, of re 'jlaceable units. It under stood that such replacement units may be supplied by the piano manufacturer and easily substituted for worn or damaged units by the household user and without necessity of employing skilledlabor or using any tools other than a screw-driver.

Inconnection with the feature of any easy adjustment, another object of the invention is to provide in connection with the hammer a bendable wire shank which permits an easy locating of the hammer head relative to its associated string and which adjustment may be effected after the mechanism is installed in place and without necessity of adjustingany other part of the action to effect the requisite hammer head adjustment.

Another object of the invention is to pro vide an improved form of soft pedal mechalllSlD'WlllCll features a modification of the loo energy inherent in the blow striking the strings by varying the distance of the haminer throw while maintaining the mass action of the hammer actuating mechanism.

Various other objects and advantages of the invention will be in part obvious from an inspection of the accompanying drawings and in part will be more fully setforth in the following particular description of one form of mechanism embodying my invention. and the invention also consists in certain new and novel features of construction and combination of parts hereinafter set forth and claimed.

In the accompanying drawings Figure 1 is a view in side elevation and partially in section of a piano action constituting a preferred embodiment of the invention and which is intended to represent one of a set of such actions usually installed in the piano in sets of five or six;

Figure 9 is a vertical sectional view taken centrally through the carriage shown in elevation in Fig. 1; and

Figures 3 and l are each transverse sectional views taken respectively on the lines 323 and l. l of Fig. 1.

In the following description and in the claims, parts will be identified by specific names for convenience of expression but they are intended to be as generic in their application to similar parts as the art will permit.

In the drawings there is shown certain supports 10 constituting fixed parts of the piano casing, together with alrey-board 11 on which is positioned one of the keys 12 of the manually actuated type, together with its associated string 13.

Resting on and supported entirely by the key 12 is an abstract let. This abstract is in the form of a straight rod, guided for vertical movement in a pair of apertures 15 and extending through vertically spaced parts 17 and 18 of the support 10. It is a feature of this construction to minimize frictional resistance to the movement of the abstractand preferably the parts of the abstract which extends through the apertures are formed of thin wire and the apertures are outlined by felt sleeves 19 designed to constitute anti-friction guideways. Opposite ends of the abstract are defined by rounded heads 20 and 21 of which the lower head bears on the key and is entirely supported thereby. The top of the upper head 20 provides a rounded bearing surface 2:2 for supporting and limiting the recoil movement of a hammer actuating mechanism hereinafter more fully described.

F or the purpose of varying the operative length of the abstract and in this way adjust the normal inoperative position of the hammer actuating mechanism, the abstract is f rmed of a plurality of parts in screw threaded engagement to permit axial adjustment. In the form illustrated the abstract includes a body portion 23 into one end of which is threaded one end of one of the wires 2i, constituting the connect-ions between the heads and tie body portion of the abstract. Smooth portions 25 of these wires move through the felt lined apertures 15 and 16. This variable length abstract consti utes all of the necessary regulation for the action and as this abstract is readily accessible through the bottom front of the piano casing the necessary regulation is thus confined to a single readily accessible place in the piano.

A support 26 herein shown to be a. pair of'spaced uprights is mounted on the support 10 and is secured in removable posi tion by means of a pair of screws 24' and 28. It is herein suggested that a pair of tnese supports be assemliled as a readily removable unit and in either case this support will be identified. hereinafter as a block. in some cases where there availal'ile room there may be used one block and associated mechanism for each string and abstract but in practice it preferable to' assemble the hannner actuating mechanisms in sets oi: four or five as suggested in the showing in Figure 3 and to tie the sets together. This is attained by the use of some suitable form of fastening means which will permit the replacement at will of any one set or of any one block and its associated mechanism without disturbing the other sets in the piano or the other blocks in the set.

Referring to the single block as eisi ilanatory of any block in the set there is shown a pivot pin seat 28 in which is mounted a pivot pin 29 and which pivot pin will have alength sufficient to constitute the pivot pin of all of the blocks in a set, as shown in Figure 3. The pivot pin is secured in position by means of a pair of linger pieces 30, each in turn held in place by one of the screws 28. The pivot wire extends beyond opposite ends of each set and one such projecting portion of the wire of an adjacent set is shown at :31 secured in place by the finger of an end bloc It is of course, within the scope of this disclosure to provide a separate pivot pin for each block.

Pivotally mounted in each block and rcmovable bodily therewith is a carriage or hammer actuator 32 in the form of a lever which extends horizontally and rests on the bearing surface 22 of its associated abstract. The carriage is weigl'ited so that normally it rests on the abstract but is otherwise free of the abstract so that the abstract may fall away from the carriage without carrying the carriage with it. The carriage is limited in its hammer atuating movement, under the lifting effect of the abstract, by engaging the underside of an overhanging stop 33 constituting a fixed part of the piano casing.

The carriage is provided on. the side of its fulcrum adjacent the abstract with an upstanding post 34 havinga head 35. The edge of the head facing the hammer shank 36 hereinafter described is provided with a V-shaped slot 37. The hammer shank 36 carries a similar shaped wedge 38 designed to engage in the slot. The wedge and slot coact to constitute a shock absorbing device for dampening out the tendency of the hammer to vibrate" in' its recoil movement from the string. The inter-engaging faces of this device are defined by felt facings 39 and 404 proper operation of this Wedging device that the angularity of the Wedge and its associated slot be properly designed. and this will usuallybe attained by experimenting with the particular action under considera tion. The angle must not be so small that the hammer is frozen in position following a powerful recoil but should be free to respond repeatedly to a rapidly succeeding actuation. On the contrary the angle should not be so wide as to fail to hold the hammer against a suc-ceeding rebound towards the string. In one practical embodiment of the invention wherefelt was used as a timing the angle of the slot was about 9.

The hammer includes a butt 41 also pivotally mounted on the same pivot pin 29 which mounts the carriage. It is another featureofthis disclosure that there is but one pivotal connection in the entire action. This pivot-his utilized not only to'pivotally mount the hammer but also to pivotally mount every element necessary to actuate the same directly from the abstract.

The hammer is provided with the usual string striking head 42 and a light spring 42' tends normally to hold the hammer in engagement with the wedging device. It is a usual practice to form all parts of such hamn'lers of wood, usually glued together so that each head must be properly located relative to its string before the shank is glued to the butt of the hammer. In the present disclosure the shank is made of a readily bendable wire. In this way it is possible to adjust the head by slightly distorting the wire shank after the action is mounted in place and without disturbing any other part of the action or its mounting.

The action herein featured may additionally be designed to actuate a damper of con ventionalform. In the disclosure there is illustrated a conventional form of damper 43 pivotally mounted at 44 to some fixed part of the support. The lower end of this damper is engaged by an u standing foot 45 forming the end of the plvoted carriage adjacent the string. The foot is normally It is important to the to do any e'l'lective work except to throw the hammer.

In operation the elevation of the inner end of the key in its playingoperation will act through the abstract to lift the same and thus swing the carriage about its pivotal connection and finally into engagen'ient with the stop During this entire move ment the hammer is engaged through the head 35 which is in spaced relation to the fulcrum of the hammer and this acts as a long arm lever for throwing the hammer. This'means that during the period when the carriage is moving from its normal inoperative position shown in Figure 1 into engage ment withthe stop, the hammer is acquiring momentum which has as a factor the mass action of all the moving parts fulcrumed on the pivot pin 29. The parts are so j'n'oportioned that the carriage engages the stop before the hammer head engages the strii'ig. The hammer is relatively light so that it has little mass action on recoil, but at the instant of striking the string is actingunder the force of the kick imparted thereto by the relatively massive carriage. The .hammer rotates about its pivot pin under the force of its inertia and into striking engagement with the string. It is noted that at the instant of striking the string the hammer is entirely free of its actuating mechanism. Excepting for the relativelj slight energy utilized to trip the damper into its inoperative position the entire energy inherent in the key is utilized in energizing the hammer in its string striking movement.

No part of this energy is utilized for the purpose of securing the hammer in its return to normal, inoperative position as is usual in conventional forms of such actions.

The hammer on its recoil iron. the string is dampened solely by the momentum of its recoil and wedges lightly in the friction clutch independent of the actuating mechanism and with an intensity of engagement depending solely upon the energy of recoil of the hammer away from the string and in its engagement with the felt face wedging device. v

On the release of tension on the key it falls away from the abstract and the abstract is free to fall by its own weight. In normal operation of the device this fall of: the'abstract will he assisted by the weight of the carriage hearing on the same in its recoil from the stop It may even be possible thatthe hammer engages the actual It) lfltl tor before the latter has fully returned to its normal position in which case the retreating carriage assists the hammer in giving up its energy of recoil and assists in preventing a repeated stroke of the hammer against the string.

is the point or resistance to the movement of the action is confined to the single pivotal connection at 29, and to the two slidin; bearings at 15 and 16, resistance to the movement of the parts in either their actuating or reversed direction has been minimized and in p 'actical operation there is substantially no material resistance to the mowment of the action. As a result the action is characterized by extreme rapidity of movement which is found to he particularly attractive in its use in player pianos where rapid sequence of operation is necessary to eti'ect a clear, distinct, sequence of blows on any single string when playing a rapidly repeated series of notes on that string.

As the normal position of the hammer i the distance in which the hammer must travel in order to eli'ect its operating stroke, the adjustment of this position pro- 'vides the necessary regulation and in the device disclosed this adjustmentis convenientiy provider by rotating the threaded por tion of the abstract into or out of the body portion.

By removing the screws 27 and 28 it is possible to lift the action, including the hammer and its actuating mechanism, from the piano as a unit. There is no other connection between the action and the piano except the connection provided by the screws 27 and It is possible by this construction for the piano user to be supplied with additional units which by the use of a screwdriver, can be installed in place of a damaged or worn unit. The shank of the hammer an be bent, if necessary to insure the proper striking position of the head and in this way an action can be repaired by the user and without necessity of skilled labor. Further it is possible to replace a hammer or carriage without removing the unit simply by releasing the holding screws 28, liftingthe lingers 30, which will permit the withdrawal of the carriage, or hammer, or both. Repairs can then he made to the removed parts, after which they can be readily repositioned in place all without disturbing the remaining mechanism or effecting the operation of the piano except in the removed parts.

By actuating the soft pedal the key may be partially raised to any desired extent depending on the angle through which the cam it is rotated and in th s way the normal inoperative position of the hammer head may be adjusted while playing the instrument.

By means of an action of the character described all the advai'itages of a quicl: stroke and return ot the han'imer characterizing old forms are retained and a much simplitiet structure is provided featuring economy both in manufacturing cost as well as ettleiency in operation.

While I h ve shown and described, and have pointed out in the annexed claims, ccrtain novel features of my invention, it wiil be understood that various omissions, substitutions and changes in the form and detaiis of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

Having thus described my invention, i -laim1-- 1. A piano action including a )ivoted ca 1- riage, a hammer butt pli'tii'tt to the carriaa'e and actuated thereby, a hammer carried by i butt, :1 verti ally movable ab.--;tract able of moving inde icndent of the car range and adapted to be raised into lifting; c" agemeut with the carri to lift the same on its hammer actuating s' cite, a stop tor limiting the movement of carriage in its act ating stroke and said hammer mounted to provide a movement thereof under its own inertia beyond the position of i, Ml

the carriage when in engagement with the .I

stop and into operative engagement with its associated string.

2. In a piano action, the combination of a pivotally mounted carriage, means for moving the can go on its operative direction, a hammer pivotally mounted and adapted to moved on its stringstrihing stroke by the operative n'iovement of the said means, said hammer and carriage provided with wedge fOlDlllifl elements coacting to form a if-wedge for dampening; out vibrations ot the hammer on rebound from the string.

3. In a piano action, the combination of a string, a pivoted hammer tor said stri i power member having); a limited si'i'ii) 1 ing movement in one direction, in: is tween the power member and the hammer for transiatin l the kinetic energy in the actuating stroke of the power member into a movement of the hammer in its strings striking direction and said hammer beingmounted to permit the hammer to rebound idly from the string independent or the translating means and clutching means between the hammer and translating; means for cushioning the rebound of the hammer.

t. In a piano action, the combination with a string, of an ab tract having an actuating movement in one direction for a limited distance, a pivoted hannner, a driving connection between the abstract and hammer, said hammer ha ing a freedom of movement independent of the connection, said connec tion including means for utilizing the actuatlhu lill

ing stroke of the abstract for moving the hammerin its operative Stroke toward its strmg and the rebound of the hammer from :thereon, a hammer butt carried by the carriage, a hammer carried by the butt, a single pivotal connection for both the carriage and butt, a stop for limiting the movement of the carriage on its actuating strokewhile permitting the butt to continue to turn independent of the carriage "and thus permit the hammer to travel on into its striking engagementwith its associated string under its own inertia. I

6, In a pianoaction, the combination of a hammer, a stop for limiting the recoil movement of the hammer, and means between the hammer and stop for securing thehammer against rebound, said meansincluding a V shaped wedge engaging "in a similarly shaped slot, said slot disposed in the plane of movement oit'the hammer, the interengaging faces of both the slot and wedge being covered with felt. V I

, 7. In a piano action, the combination of a pivoted carriage, constituting part of the mechanism [for actuating a hammer, a V- shaped element secured to the carriageand movable therewith. a hammer pivoted for movement concentrically of the axis of rotation oi the carriage, and a wedge shaped member carried ,by the hammer andadapted to engagein the V-shaped element and coacting therewith to form afriction clutch for dampening out the recoil vibratory movement of the hammer and a cushioning ma terial disposed between the operative faces of said friction clutch. i I

In a iano action, the combination of a pivoted carriage, constituting part of the n'iechanism for actuating a hammer, a V- shaped elementsecured to the carriage and movable therewith, a hammer pivoted for movement concentrically of the axis of rotation of the carriage, and a single, rigid wedge shaped member carried by the hammer and adapted to engage in the V-shaped ele mentand coacting therewith to form a friction clutch for dampening out the recoil vibratory movement of the hammer.

9. In a piano action, the combination of a hammer, a stop for limiting the recoil movement of the hammer, andmeans between the hammer and stop for securing the hammer against rebound, said means including a V'- shaped wedge engaging. in a similarly shaped slot and said wedge and slot disposed in the plane of movement of the hammer.

10. In a piano action, thertombination0t a 1 key, an abstract guided for vertical reciprocatory motion andcresting on the key, the upper end of the abstract providing a hammer locating seat, a hammer actuator pivotally mounted and engaging said seat, said actuatorhaving a hammer stop fixed-rigidly thereto, a hammer pivotally mounted and normally engaging said stop on the actuator and means for varying the length of the actuator thereby to vary the position of said hammer stop. 7

11. A piano action including a key, an abstractmounted for vertical reciprocatorv movement, resting entirely on said key and actuated thereby, a hammer actuator pivotally mounted and including an arm normally resting on the abstract and a hammer pivotally mounted and movable relative to the actuator actuated by the actuator in its rotary movement under, the lifting action of the key controlled abstract, and said ham mer located in its normal inoperative position by the actuatorin its engagement with the abstract and means for varying the operativelength of the abstract thereby to'vary the distance between the actuator and the key.

12. In a piano action, the combination of a fixed stop, a hammer opcrably independent of said stop, an actuator for the hammer pivotallymounted and limited by said stop in its hammer actuating movement, an ab stract for swinging the actuator in its hammer operating movement and constituting a stop seat for limiting the return movement of boththe actuator and the hammer and a single regulating means for varying the,

operative position of said seat and constitut ing the sole necessary means for regulating the action.

13. A piano action including a pair of vertically spaced supports provided with vertically aligned apertures constituting anti-friction guideways and a rod constituting an abstract guided in said apertures.

14. In a piano action, the combination of a pivotally mounted hammer, an abstract mounted for vertical reciprocatory movement, guiding means for confining the abstract to a straight line reciprocatory movement, and a single, one piece rigid lever constituting all of the means for translating the longitudinal movement of the abstract in its upward direction into the rotary movement of the hammer necessary to efi'ect its string striking stroke, and a single stop disposed in the path of rotary movement of the actuator for limiting the movement of the actuator, abstract and key in their stringstriking movement.

15. In a player piano, the combination with a support, a set of strings and a set of abstracts mounted in operative position on the support and constituting a fixed part mcchaniam tor actuating the hammer ti-om one of the ahstracta.

16. Au articl" o't inanirhirturc constitut int: :1 replaceable unit designed to be mounted 111 a 11 1 as part of its action. aaid unit including! :1 support provided with means tor aecurin r the same in piece. :1 hanuner pivot d to eaid Support and mechanism for trans ferrinizaction from an abatract forming part ot the action in the piano to the hammer "forming part of the replaceable unit.

17.111 a piano action. the combination with a lie actuated abstract and string,

of :1 :nountinc DIOVltllDQ' a nvot nu 5:1 .1-

port. a pivot pin engaging Hilltl niountinc i readil re: 1:: 'able meana tor f-'t('1':1l:11' pin in place and string striking mechanism carried by the pin and reu'iov: ble therewith bodily from the remainine parts of the action.

13in a p ano action. the combination with a key actuated aliistract and :1 string, ol :1 rear, Ely replace: blc unit prorided with :1 pivot pin seat. :1 pivot pin remm'ahl poaitioi'ied in said seat. meana for locking: the pin in place and a hammer and associated :utuatinq mechanism pirotally mounted on said removable pin.

19. In a player piano. the combination with a support. :1 act of strings and a set ot ab- 5: 'racts mounted in operative position on the support and constituting a fixed part of the piano construction, a readily replaceable unit adapted to be inatalled in position on said support. said unit including a hannner and all the necessary mechanism for act-nat- Eng the hammer from the abstract.

20. In a player action. the combination of :1 string, a hammer there tor i1 eluding); a hammer butt pivotally mounted. :1 hammer head and a bendable \vire constituting the hammer shank connecting the butt and head. said \rire shank constituting" the means tor adjusting the head to its proger striking position relative to the etrinilj.

in a player action. the combination ot' a string. :1 hammer therefor mounted tor rotary movement about :1 fixed axis, hammer including a bendable part count itutir the mea tor adjusting the head ol" the hammer rclatzre to the string.

In a piano action. the combination 0t :1 single driving connection for tranelatinc' a l near nnr emcnt of an abstract into a rota r movement (it :1 hammer. naid connection beinw pirotally mounted and provided on one Sslitl aide with an abstract blow receiving: lace. and prorided with rigid extension c n- Qtltlltlllf: a hammer engaging member fixed in position relative to the axis of rotation of said com'iection and adapted to strike the han'imer.

A. piano actionv lllClllfllllQ an :distraet mounted accurately tor vertical reciprocatory uuzrcinent. harinn' a lower cud adapted. to rest on :1 key and having its upper end fashioned to hear on and lift a hammer actuator.

Signer at Yen'arlz. in the county of Essex and vState ot New Jersej, this twelfth day o't April. A. D. 1923.

CHARLES ElVEN (h-U'IERON, Qln. 

